Low-temperature/beol-compatible highly scalable graphene synthesis tool

ABSTRACT

In one aspect, a highly scalable diffusion-couple apparatus includes a transfer chamber configured to load a wafer into a process chamber. The process chamber is configured to receive the wafer substrate from the transfer chamber. The process chamber comprises a chamber for growth of a diffusion material on the wafer. A heatable bottom substrate disk includes a first heating mechanism. The heatable bottom substrate disk is fixed and heatable to a specified temperature. The wafer is placed on the heatable bottom substrate disk. A heatable top substrate disk comprising a second heating mechanism. The heatable top substrate disk is configured to move up and down along an x axis and an x prime axis to apply a mechanical pressure to the wafer on the heatable bottom substrate disk. While the heatable top substrate disk applies the mechanical pressure a chamber pressure is maintained at a specified low value. The first heating mechanism and the second heating mechanism can be independently tuned to any value in the working range.

CLAIM OF PRIORITY

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/218,498, filed on 6 Jul. 2021, and titled WAFER-SCALECMOS-COMPATIBLE GRAPHENE SYNTHESIS TOOL. This provisional application ishereby incorporated by reference in its entirety.

BACKGROUND

Solid-phase diffusion of atoms in a “material stack” forming a“diffusion-couple” can be leveraged to synthesize high-qualitythin-films at relatively low temperatures, needed in a wide range ofapplications covering microelectronics, optoelectronics, bioelectronics,quantum computing, and many more. However, enabling such solid-phasediffusion assisted thin-film growth; particularly over large“wafer-scale” (e.g. 200 mm, 300 mm, etc.) surfaces, and withinreasonable growth times, require design and fabrication of novelapparatus that can allow uniform application of a wide range oftemperatures and pressures over the entire surface area of thesemiconductor wafer or any other substrate forming the diffusion-couple.A core component of such an apparatus is a reactor that is not onlycapable of hosting such large area substrates but also allow achemically purged environment, heated large-area substrates withnear-zero temperature non-uniformity, as well as facile mechanisms toapply relatively large and uniform mechanical pressures (e.g. up to 1000psi, etc.) to the diffusion-couple. It is noted that in some examples,atmospheric pressure can be utilized.

An imminent need for such a large-area diffusion-couple is in theemerging field of atomically-thin two-dimensional (2D) materials,particularly graphene or multi-layered-graphene (MLG) (essentially asingle or multiple atomic layers of carbon atoms arranged in a hexagonallattice), that must be directly synthesized over a desired substrate(typically a dielectric or a metal) without the need for a transfer-stepthat is considered unfeasible and cost-ineffective in the mainstreamelectronics (or CMOS) industry. Such graphene/MLG layers are preferredmaterials in several back-end-of-line or BEOL (refers to process stepsin chip manufacturing after the formation of the active devices such astransistors and diodes) applications, particularly on-chipinterconnects. However, BEOL interconnects must be synthesized under astrict thermal budget of <500° C. to avoid any damage to the underlyingactive devices (e.g. transistors, diodes, etc.).

Recent advances in graphene/MLG synthesis at BEOL-compatibletemperatures have brought to the forefront the utility of thediffusion-couple for graphene/MLG growth, where a layer of carbon-source(e.g. in the form of powder, slurry, or amorphous-carbon film) depositedover a sacrificial metallic film (such as Nickel) lying over a SiO2/Sisubstrate forms the diffusion-couple. Application of appropriatemechanical pressure (65-80 psi) on the carbon source at a relatively lowtemperature (<450° C.) has been shown to be sufficient to allowhigh-quality graphene/MLG growth, albeit over relatively small (1-2inches) substrates. Hence, to allow this technique to be integrated inthe mainstream CMOS technology, a scaled up (200/300 mm)diffusion-couple apparatus needs to be designed and fabricated. Thistechnique/apparatus is also extendable to a wide range of substrates ofdifferent geometries and configurations and to other applications thatinherently require a low thermal budget (<500° C.).

SUMMARY OF THE INVENTION

In one aspect, a highly scalable diffusion-couple apparatus includes atransfer chamber configured to load a wafer into a process chamber. Theprocess chamber is configured to receive the wafer substrate from thetransfer chamber. The process chamber comprises a chamber for growth ofa diffusion material on the wafer. A heatable bottom substrate diskincludes a first heating mechanism. The heatable bottom substrate diskis fixed and heatable to a specified temperature. The wafer is placed onthe heatable bottom substrate disk. A heatable top substrate diskcomprising a second heating mechanism. The heatable top substrate diskis configured to move up and down along an x axis and an x prime axis toapply a mechanical pressure to the wafer on the heatable bottomsubstrate disk. While the heatable top substrate disk applies themechanical pressure a chamber pressure is maintained at a specified lowvalue. The first heating mechanism and the second heating mechanism canbe independently tuned to any value in the working range (e.g. from roomtemperature to 500° C.).

In another aspect, a method for migration of a deposition materialacross a diffusion couple deposited on a substrate to a substratesurface includes using a reactor system to facilitate the migration ofone or more diffusion materials across a diffusion couple to a substrateby applying a specified pressure to facilitate the migration of the oneor more diffusion materials across the diffusion couple to thesubstrate, and applying a temperature to facilitate the migration of theone or more diffusion materials across a diffusion couple to thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application can be best understood by reference to thefollowing description taken in conjunction with the accompanyingfigures, in which like parts may be referred to by like numerals.

FIG. 1 illustrates an example top-view of a process chamber and atransfer chamber of a carbon-source synthesis tool, according to someembodiments.

FIG. 2 illustrates an example schematic view of the internal elements ofthe process chamber, according to some embodiments.

FIG. 3 illustrates an example graphene synthesis tool process, accordingto some embodiments.

FIG. 4 illustrates an example process for migration (e.g. diffusion) ofa deposition material across a diffusion couple metal deposited on asubstrate forming a diffusion-couple, to a substrate surface, accordingto some embodiments.

FIG. 5 illustrates another example process for migration of a depositionmaterial across a diffusion couple metal deposited on a substrate to asubstrate surface, according to some embodiments.

FIG. 6 illustrates an example process that uses top and bottom heatersto compress a substrate with uniform pressure and temperature, accordingto some embodiments.

The Figures described above are a representative set and are notexhaustive with respect to embodying the invention.

DESCRIPTION

Disclosed are a system, method, and article of manufacture forlow-temperature/BEOL-compatible highly scalable graphene synthesis tool.The following description is presented to enable a person of ordinaryskill in the art to make and use the various embodiments. Descriptionsof specific devices, techniques, and applications are provided only asexamples. Various modifications to the examples described herein will bereadily apparent to those of ordinary skill in the art, and the generalprinciples defined herein may be applied to other examples andapplications without departing from the spirit and scope of the variousembodiments.

Reference throughout this specification to “one embodiment,” “anembodiment,” “one example,” or similar language means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the presentinvention. Thus, appearances of the phrases “in one embodiment,” “in anembodiment,” and similar language throughout this specification may, butdo not necessarily, all refer to the same embodiment.

Furthermore, the described features, structures, or characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. In the following description, numerous specific details areprovided, such as examples of programming, software modules, userselections, network transactions, database queries, database structures,hardware modules, hardware circuits, hardware chips, etc., to provide athorough understanding of embodiments of the invention. One skilled inthe relevant art can recognize, however, that the invention may bepracticed without one or more of the specific details, or with othermethods, components, materials, and so forth. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

The schematic flow chart diagrams included herein are generally setforth as logical flow chart diagrams. As such, the depicted order andlabeled steps are indicative of one embodiment of the presented method.Other steps and methods may be conceived that are equivalent infunction, logic, or effect to one or more steps, or portions thereof, ofthe illustrated method. Additionally, the format and symbols employedare provided to explain the logical steps of the method and areunderstood not to limit the scope of the method. Although various arrowtypes and line types may be employed in the flow chart diagrams, theyare understood not to limit the scope of the corresponding method.Indeed, some arrows or other connectors may be used to indicate only thelogical flow of the method. For instance, an arrow may indicate awaiting or monitoring period of unspecified duration between enumeratedsteps of the depicted method. Additionally, the order in which aparticular method occurs may or may not strictly adhere to the order ofthe corresponding steps shown.

Definitions

Back End Of Line (BEOL) is the second portion of IC fabrication wherethe interconnects and other elements are formed between and over theindividual devices on the wafer (e.g. the metallization layers)separated by intra-layer or inter-layer insulators.

Complementary metal-oxide-semiconductor (CMOS) is a type ofmetal-oxide-semiconductor field-effect transistor (MOSFET) fabricationprocess that uses complementary and electrically symmetrical pairs ofp-type and n-type MOSFETs for logic functions.

Grain boundary (GB) is the interface between two grains and/orcrystallites in a polycrystalline material.

Graphene is an allotrope of carbon consisting of a single layer of atomsarranged in a two-dimensional honeycomb lattice.

Graphene nanoribbons (GNRs) are strips of graphene with width less thanone-hundred (100) nm.

Graphite is a layered crystalline form of the element carbon with itsatoms arranged in a hexagonal structure within the layers.

Piezoelectricity is the electric charge that accumulates in certainsolid materials in response to applied mechanical stress.

Resistance temperature detectors (RTDs), are sensors used to measuretemperature. RTD elements can consist of a length of fine wire wrappedaround a heat-resistant ceramic or glass core but other constructionsare also used.

Silicon dioxide is an oxide of silicon with the chemical formula SiO₂.

Wafer is a thin slice of semiconductor (e.g. a crystalline silicon(c-Si)) used for the fabrication of integrated circuits, etc.

Example Low-Temperature/BEOL-Compatible Highly Scalable GrapheneSynthesis Tool

It is noted that the following example embodiments discuss a graphenesource by way of example. However, other carbon-sources (including anycarbon carrying compound) can be utilized in other example embodiments.

FIG. 1 illustrates an example top-view of a process chamber and atransfer chamber of a carbon-source synthesis tool 100, according tosome embodiments. It is noted that in other example embodiments, otherdiffusion materials (other elements in the periodic table suitable for aspecific diffusion metal and application) than carbon-sources can beutilized. Carbon-source synthesis tool 100 can be alow-temperature/BEOL-compatible scalable graphene (and/or other carbonsource) synthesis tool. Carbon-source synthesis tool 100 includestransfer chamber 102. Transfer chamber 102 is used to load the wafer.The wafer can be various sizes (e.g. 300 mm, 200 mm, 150 mm, etc.). Anoperator/user can place the wafer in transfer chamber 102. The transferchamber 102 is then closed and sealed. The pressure of the transferchamber 102 is equalized with the pressure of the process chamber 104.Once the pressure is equalized, the wafer is then pushed to the processchamber 104. It is noted that the wafer can be returned to the transferchamber 102 after implementation of the deposition and other fabricationmethods.

The process chamber 104 and the transfer chamber 102 are connected via aslit valve 108. Slit valve 108 automatically opens once the pressuresinside the two chambers are equalized.

The process chamber 104 is the main chamber for growth of graphene(and/or other carbon material) on the wafer. A slightly larger than 300mm sized substrate is located in the process chamber 104 (e.g. seeheated bottom substrate 208). Process chamber 104 is equipped with aheater system. A heated top substrate disk is located in the processchamber 104 as well (e.g. see heated top substrate 206). The heated topsubstrate disk has its own heating mechanism as well (e.g. see heatingpower supply 202). In this way, both the lower substrate disk on whichthe wafer is placed and the heated top substrate disk can be heatedindependently. For example, the lower substrate disk can be heated andthe top substrate disk can be kept at approximately room temperature (orvice versa). The liner surfaces can be made of graphite though othermaterials such as aluminum nitride, quartz, silicon carbide coatedgraphite, etc. can be employed. Several such materials arepossible—generally speaking materials which permit good heat transferand distribution of pressure can be considered. Flatness and surfacefinish of the liner can be a key to ensure appropriate heat and pressuredistribution.

Mechanical/turbo pump 108 can be used to control pressure in processchamber 104 and/or transfer chamber 102. Mechanical pump(s) can be usedto lower pressure in process chamber 104 (e.g. 10⁻³ torr). The turbopump can be a more powerful pump that is used to lower the pressure evenfurther (e.g. 10⁻⁷ torr). Low pressure is desired to purge the chamberof any impurities.

Electrical control 110 can be used to operate carbon-source synthesistool 100. Electrical control 110 can include a computer processor andsoftware systems. Users can input commands, view status of variousoperations of carbon-source synthesis tool 100, etc.

FIG. 2 illustrates an example schematic view of the internal elements ofprocess chamber 104, according to some embodiments. Wafer transferchamber 214 provided shows transfer of the wafer back and forth totransfer chamber 102 from process chamber 104. Heated bottom substrate208 can be fixed and can be heated to a specified temperature (e.g. 500°C., etc.). Heat power supply 220 can maintain heat on the heat bottomsubstrate 208. This can be done with a ±3° C. uniformity (and/ornear-zero non-uniformity) across the heat bottom substrate 208. Heatedtop substrate 206 can move up and down along the x and the x prime axis.Heat top substrate 206 has an independent heating supply (e.g. heatpower supply 202). Heated top substrate 206 can be operated withhydraulic cylinder 204, a motor, and the like. Heated top substrate 206can be moved to provide mechanical pressure. By way of example, thispressure can be 50 to 125 psi. The wafer is inserted on top of heatedbottom substrate 208. While the heated top substrate 206 appliespressure the chamber pressure is maintained at a low value. This can befor example, 10⁻⁶ to 10⁻⁷ torr to prevent contamination of the growthprocess. Pressure can be regulated by mechanical/turbo pump 216.

An example operation of process chamber 104 is now discussed. Processchamber 104 can be used to deposit/grow a number of layers (e.g.monolayer or few-layer graphene structures, multi-layer graphenestructures). To grow graphene, a graphene source is deposited on a filmof nickel (e.g. a 100 nm in thickness, etc.). The graphene source(and/or other carbon-source) can be, inter alia: a graphite powder, aliquid/slurry form as a solvent with graphite, a layer of amorphouscarbon deposited on nickel. Different deposition methods and tools canbe utilized to deposit the 100 nm of nickel followed by the carbonsource. The mechanical pressure breaks up the graphite source (e.g.amorphous carbon film) that then diffuses through the nickel and thenrecombines on the other side of nickel on top of the target (such asdielectric) substrate. Once this is done, the nickel film and amorphouscarbon is then removed.

FIG. 3 illustrates an example graphene synthesis tool process 300,according to some embodiments. Graphene synthesis tool process 300 canbe used to operate carbon-source synthesis tool 100. Graphene synthesistool process 300 can grow graphene at relatively low temperatures (e.g.300-450° C., etc.). It is noted that when process chamber 104 is below^(˜)450° C. then it can be compatible with a CMOS/BEOL thermal budget.BEOL are process steps that take place after front end of linetransistors are completed. Once a fabrication process has builttransistors in wafer, then the subsequent processing steps should bewithin the ^(˜)450° C. thermal budget to avoid damage to the transistorsand various diffusions that lead to shorts and reliability issues.

Graphene synthesis tool process 300 synthesize graphene while the numberof layers can be controlled by adjusting process parameters. Graphenesynthesis tool process 300 can directly grow on top of any substrate(e.g. dielectric substrate, metallic substrate, etc.). Graphenesynthesis tool process 300 can synthesize graphene to thin/few layercoating of a metallic substrate.

More specifically, in step 302, graphene synthesis tool process 300 canimplement low-temperature (e.g. <450° C.) compatible with a CMOS/BEOLthermal budget. In step 304, graphene synthesis tool process 300 canimplement a direct (e.g. transfer-free) graphene synthesis on varioussubstrates. In step 306, graphene synthesis tool process 300 canimplement controlled thickness from monolayer to multilayer.

EXAMPLE EMBODIMENTS

An example embodiment can start with a wafer (e.g. Si/SiO₂) then deposita thin film of a catalyst metal thin-film such as nickel. The morphologyof the catalyst film can be tuned during the deposition or afterdeposition (e.g. via annealing etc.) to meet specific application needs.Then deposit a uniform distribution of carbon-source on top of Ni. Apressure of 65 to 85 psi is applied on the graphene. A disc with adiameter slightly larger than the 300 mm wafer can be used. Thesubstrate can be heated to 300° C. to 450° C. Once the pressure isapplied, a portion of the carbon items are diffused through the Ni. Thecarbon-source/Ni/SiO₂/Si can act as a diffusion-couple. The carbon atomscan recombine on the other side of the Ni (e.g. facing the SiO₂) to forma monolayer, few-layer, or multilayer graphene.

Various processing steps can then be implemented (e.g. removingremaining graphite, removing catalyst (Ni) layer, etc.).

Instead of an SiO₂, the substrate can be copper or another metal (suchas cobalt, ruthenium, molybdenum, tungsten, or an alloy metal, etc.), ora low dielectric constant (low-k) material such as poroussilicon-dioxide or hydrogen silsesquioxane (HSQ), or even any patternedsubstrate formed with metals and dielectrics, etc. In this embodiment,the modification can include a sacrificial layer of amorphous carbonbetween the Ni and the Cu. In this way, the Ni and the Cu can beprevented from forming an alloy. In other examples, other metals caninclude, inter alia: Co, Ni, Fe (as both a substrate and/or a catalyst),molybdenum, etc., or a metal compound.

The thicknesses of the substrates and catalysts can be set (e.g. 100 nm,etc.). The number of layer(s) of graphene (i.e., its thickness) requiredcan be a function of thickness of Ni along with other process parametersincluding time, temperature, pressure, and grain-size of the catalystfilm.

The substrate wafer can be 300 mm or 200 mm or smaller/larger (450 mm).A temperature controller can be used to keep the temperature to roomtemperature (^(˜)25° C.) to 500° C., or higher as long as processcompatibility is met. The graphite powder can be spread in a uniform orpre-patterned manner. A chuck can be used to press down on the uniformlydistributed graphite. Other carbon-containing compounds can also be usedas a substitute.

Pressure on the substrate can be applied by means of mechanical forcefor instance by employing an instrument such as a chuck, or via anynon-contact means such as increasing the substrate environment pressureby, for instance, using a gas pressure (1 bar to several 100's of bars).A single substrate or multiple substrates as batches can be processed atonce. In addition, the gas can be normal air or a specific gas such asAr, N2 or a mixture of many such gases etc.

Application of heat can be from any source capable of generating atemperature on the substrate. In some embodiments, the top substratedisk can be heated and/or the bottom substrate disk can be heatable. Insome embodiments, the top substrate disk and/or the bottom substratedisk may not be heatable, and there can be another heat source such as,for example, the pressure chamber walls, etc.

Example Systems and Methods for Migration of a Deposition MaterialAcross a Diffusion Couple Deposited on a Substrate to a SubstrateSurface

Example systems and methods can provide for the migration of adeposition material across a diffusion couple deposited on the substrateto the substrate surface. This approach provides many advantages for thedeposition of the material.

FIG. 4 illustrates an example process 400 for migration of a depositionmaterial across a diffusion couple deposited on a substrate to asubstrate surface, according to some embodiments. Process 400 can use areactor system to facilitate the migration of one or more diffusionmaterials across a diffusion couple to a substrate by implementing thefollowing steps. In step 402, process 400 can apply a specified pressureto facilitate the migration of the one or more diffusion materialsacross the diffusion couple to the substrate. In step 404, process 400can apply a temperature to facilitate the migration of the one or morediffusion materials across a diffusion couple to the substrate.

FIG. 5 illustrates another example process 500 for or migration of adeposition material across a diffusion couple deposited on a substrateto a substrate surface, according to some embodiments. Process 500provides the ability to deposit a material that it may not be possibleto deposit directly using conventional methods. For example graphene isnot known to be directly depositable on silicon. Process 500 permitsthis to be done. It is noted that the grain and other materialstructures of the deposited material may be tailored by appropriatelyvarying the structure of the diffusion couple.

In step 502, process 500 deposits the diffusion couple on the substrateby various means, including the most commonly used ones and thendepositing some form of the material to be deposited on the substrate ontop of the diffusion couple. This may herein be referred to as theprepared substrate or the layer substrate.

In step 504, process 500 places the prepared substrate into anenvironment of high pressure and high temperature, ranges of which arespecified in this document, for a period of time.

In step 506, process 500 can perform the application of heat isaccomplished through, inter alia: resistive heating, radiative heating,gas heating and the like.

In step 508, process 500 can apply pressure as well. This can beimplemented through, inter alia: mechanical means, through gas pressure,through flexible membranes, through liquid pressure, and the like.

Example Use Case: Reactor with Mechanical Application of Pressure andDirect Heating

FIG. 6 illustrates an example process 600 that uses top and bottomheaters to compress a substrate with uniform pressure and temperature,according to some embodiments. Carbon-source synthesis tool 100 can bemodified and/or otherwise used to implement the present exampleembodiment. The substrate is placed on a pedestal through means of ahandler typical to the equipment industry. The pedestal has the abilityto heat the substrate through direct contact. Note that the contactmaterials may be varied through use of appropriate liner materials. Atop moving heater then moves down and puts the substrate under pressurewhile at the same time heating it. When the process is completed, thesubstrate is returned out from the reactor (e.g. the process chamber ofFIG. 2 supra, etc.).

In step 602, the application surfaces of the top and bottom heater are,are parallel to the substrate, and sufficiently compliant so as to notdamage the substrate. This is accomplished by providing sufficientclearance and play and compliance to the top heater mechanism, as wellas by providing a layer of compliance if needed to the applicationsurfaces in step 604.

In step 606, the reactor may also be provided with the means to put thesubstrate under vacuum and expose it to other gases such as, inter alia,N2, Ar, He, and the like to optimize the process. Hence the reactor maybe equipped with vacuum pumps as well as gas lines and a gas panel toensure ability to put the substrate under various environments.

In step 608, the reactor may be interfaced to equipment that can deliverthe substrates to and from the reactor. For example in the case of waferprocessing the reactor may be attached to the facet of a transferchamber that is equipped with a wafer handling robot that operates underhigh vacuum. In some examples, a slit valve can be provided to isolatethe reactor from the rest of the system. A plurality of reactors may beattached to the transfer chamber to facilitate higher throughputs orproduction rates. There can also be reactors that deposit the diffusioncouple as well as the source material are added to the transfer chamberthereby permitting the creation of the layers on the substrate as wellas the deposition of the final material on the same system. The designof these reactors for proper interface to production equipment that istypically used for the purpose is an essential part of the design.

In step 610, process 600 provides in situ sensors (e.g. in the reactor,etc.) to ensure that the pressure and temperature distributions in turnresult in optimal migration of the deposition material across thediffusion couple. For example the pressure can be calibrated andmonitored through the use of a pressure sensor on the step of thepedestal, through monitoring of the current drawn by the motor applyingthe pressure between the surfaces, through use of flexures configured asstrain gauges embedded in the liner material and the like. Likewise thetemperature can be monitored using thermocouples and RTDs mounted in thepedestals, use of IR sensors, phosphorus-based sensors, and the like.

In step 612, process 600 provides software controls to ensureappropriate application of the process parameters in the right sequenceand duration.

Other configurations of the reactor that apply other forms of heat andpressure on the substrate are now discussed. It is noted that theaforementioned configuration is just one of many. Alternateconfigurations could include, inter alia:

-   -   Heated membraned subject to high pressure (either pneumatic or        hydraulic for example);    -   Clamshell configurations with high temperature and high pressure        heated N2, Ar, other such gases;    -   Large batch reactors with the same characteristics as discussed        supra;    -   Clamshell in which bottom heater but her heated high temperature        gas to accomplish the pressure function and maintain        temperature;    -   Quartz body with substrate placed on a susceptor and inductively        heated and pressure loading accomplished using high pressure        gas; and    -   May also include an array of lamps in a quartz body for final        temp control.

By way of example, the reactors outlined above facilitate the depositionof materials through diffusion couples, as in the use of deposition ofgraphene onto a silicon wafer across a nickel layer. The depositionmethod using diffusion couples can be applied to a whole host ofdeposition materials and diffusion barrier materials.

The following sections provide certain ranges of operation for thesystem, as well as parameter ranges for desired material structures,composition, and the like for optimal process results.

As noted earlier the use of this method to permit migration of onematerial across a diffusion couple permits deposition of a material onsubstrate where it may previously not have been possible through othertraditional deposition methods (e.g. amorphous carbon is difficult todeposit directly on Si to form graphene). The systems described herefacilitate the growth of graphene on Si by impregnating throughapplication of pressure and temp amorphous C deposited on a Ni layerthat is in turn deposited on a Si wafer, etc.).

It is noted that the reactor can be implemented as a batch reactorand/or single substrate reactor. It is noted that in single substrateconfigurations finer substrate to substrate process control than with abatch reactor can be accomplished. A method of creating a batch processwith a single wafer architecture can also be to process a stack ofwafers between the two heaters.

CONCLUSION

Although the present embodiments have been described with reference tospecific example embodiments, various modifications and changes can bemade to these embodiments without departing from the broader spirit andscope of the various embodiments. Accordingly, the specification anddrawings are to be regarded in an illustrative rather than a restrictivesense.

1. A scalable diffusion-couple apparatus comprising: a transfer chamberconfigured to load a wafer into a process chamber; the process chamberconfigured to receive the wafer substrate from the transfer chambercomprising: a chamber for growth of a diffusion material on the wafer; aheatable bottom substrate disk comprising a first heating mechanism,wherein the heatable bottom substrate disk is fixed and heatable to aspecified temperature, and wherein the wafer is placed on the heatablebottom substrate disk; a heatable top substrate disk comprising a secondheating mechanism, wherein the heatable top substrate disk is configuredto move up and down along an x axis and an x prime axis to apply amechanical pressure to the wafer on the heatable bottom substrate disk,and wherein while the heatable top substrate disk applies the mechanicalpressure a chamber pressure is maintained at a specified low value;wherein the first heating mechanism and the second heating mechanism areheated independently, and wherein the wafer is placed on the heatablebottom substrate.
 2. The highly scalable diffusion-couple apparatus ofclaim 1, wherein the diffusion material comprises a carbon material. 3.The highly scalable diffusion-couple apparatus of claim 2, wherein thecarbon material comprises a graphene material.
 4. The highly scalablediffusion-couple apparatus of claim 1, further comprising one or morepumps configured to control a pressure value in the process chamber tobetween 10⁻³ torr to 10⁻⁷ torr.
 5. The highly scalable diffusion-coupleapparatus of claim 1, wherein the wafer comprises a silicon wafer of a300 mm diameter, a 200 mm diameter, or a 150 mm diameter.
 6. The highlyscalable diffusion-couple apparatus of claim 1, wherein the heatablebottom substrate disk comprises a 300 mm disk.
 7. The highly scalablediffusion-couple apparatus of claim 1, wherein the heatable bottomsubstrate disk is heated to 500° C. with a ±3° C. uniformity across theheat bottom substrate disk while the heatable top substrate disk appliesthe mechanical pressure to the wafer.
 8. The highly scalablediffusion-couple apparatus of claim 7, wherein the heatable topsubstrate disk applies 50 psi to 125 psi of mechanical pressure to thewafer.
 9. The highly scalable diffusion-couple apparatus of claim 1,wherein the heatable top substrate disk applies the mechanical pressurewhile the chamber pressure is maintained at a 10⁻⁶ to 10⁻⁷ torr toprevent contamination of a growth process.
 10. The highly scalablediffusion-couple apparatus of claim 1, wherein a direct synthesis ofhigh-quality atomically-thin film is performed in the process chamber.11. The highly scalable diffusion-couple apparatus of claim 1, whereinthe scalable diffusion-couple apparatus is integrated in a Complementarymetal-oxide-semiconductor (CMOS) microelectronics manufacturing process.12. The highly scalable diffusion-couple apparatus of claim 1, wherein aliner surface is composed of graphite.
 13. The highly scalablediffusion-couple apparatus of claim 1, wherein the liner comprises anAluminum Nitride or a SiC coated graphite.
 14. A method for migration ofa deposition material across a diffusion couple deposited on a substrateto a substrate surface comprising: using a reactor system to facilitatethe migration of one or more diffusion materials across a diffusioncouple to a substrate by; applying a specified pressure to facilitatethe migration of the one or more diffusion materials across thediffusion couple to the substrate, and applying a temperature tofacilitate the migration of the one or more diffusion materials across adiffusion couple to the substrate.
 15. The method of claim 14, whereinthe reactor system uses a mechanical means to apply the pressure tofacilitate the migration of the one or more diffusion materials acrossthe diffusion couple to the substrate, and wherein the mechanical meanscomprise a pneumatic mechanical means, a hydraulic mechanical means, ora Piezoelectric array.
 16. The method of claim 14, wherein the reactorsystem uses a flexible pressurized membrane to apply the pressure tofacilitate the migration of the materials across a diffusion couple tothe substrate.
 17. The method of claim 14, wherein the step of applyinga temperature to facilitate the migration of the one or more diffusionmaterials across a diffusion couple to the substrate comprising: usingresistive heating through a direct contact or an indirect contact toapply the temperature to facilitate the migration of the one or morediffusion materials across the diffusion couple to the substrate. 18.The method of claim 14, wherein the step of applying a temperature tofacilitate the migration of the one or more diffusion materials across adiffusion couple to the substrate comprising: using a heated gas toapply the temperature to facilitate the migration of the one or morediffusion materials across the diffusion couple to the substrate. 19.The method of claim 14, wherein the step of applying a temperature tofacilitate the migration of the one or more diffusion materials across adiffusion couple to the substrate comprising: using radiative heating toapply the temperature to facilitate the migration of the one or morediffusion materials across the diffusion couple to the substrate. 20.The method of claim 14 further comprising: wherein the step of applyinga temperature to facilitate the migration of the one or more diffusionmaterials across a diffusion couple to the substrate comprises: using aninductive heating of a carrier on which the substrate sits to facilitatethe migration of the one or more diffusion materials across a diffusioncouple to the substrate; using an approximate compliance in one or moremechanisms for a direct pressure application to ensure a uniformpressure on the substrate and to prevent a breakage of the substrate;using a compliant high conductivity materials at the pressureapplication surfaces to ensure uniform application of pressure withoutbreakage of the substrate; using a current draw from a top mechanism tomeasure the pressure applied to the substrate; using a pressuretransducer to measure the pressure applied to the substrate; using aplurality of flexures and leaf springs configured as strain gauges andembedded in the pedestals to measure the pressure applied to thesubstrate; and using a plurality of reactor configurations capable ofprocessing multiple substrates for batch processing of the substrates.